1. Field of the Invention
The present invention relates to a system, a method, and a computer readable medium for micropayment, specifically to a system, a method, and a computer readable medium for micropayment with varying denomination.
2. Descriptions of the Related Art
Micropayment schemes have received growing attention recently, primarily because that these schemes provide solutions for numerous Internet based applications, for example, on-line magazine subscription, on-line database query, access to charged World Wide Web pages, and Internet pop-up advertisement, etc. Micropayment schemes allow a customer to transfer to a merchant a sequence of small amount payments in exchange for services or electronic products from the merchant. Usually, it is inappropriate to pay the total amount of money either in advance or afterwards in some applications, and this makes micropayment schemes be especially useful. For the purpose of real time bargains of the micropayment system in the network, it is essential to emphasize efficiency and safety of on-line bargains.
Taking the present micropayment system as an example, the payment involving the on-line micropayment is small, while the frequency thereof is high. Accordingly, the corresponding computational cost and the storage cost must be reduced to provide an acceptable performance for users. However, under such circumstances, the above-mentioned efficiency and safety of on-line bargains is hard to maintain in the meantime.
According to the developing trend, there are three types of micropayment schemes: counting type, one-way hash chain type and signature type.
The micropayment schemes of the counting type uses a scheme of subtracting points from the counter of a customer and adding points of the counter of a merchant as well. The disadvantage of this scheme is low safety for customers. If a bargaining dispute occurred, few protection can be provided to customers.
As to the micropayment schemes of the one-way hash chain type, a fixed currency value is used. Therefore, the computational cost for calculating the one-way hash chain is high, the above-mentioned purposes of reducing the computational cost and the storage cost for the micropayment system is hard to achieve. In addition, the micropayment schemes of the signature type needs more computational costs for calculation and transmission.
As a result, there is an essential need to provide a new micropayment scheme with balancing efficiency and safety according to the characteristics of on-line bargains for the industry to reduce the computational costs and storage costs thereof.